* {
  --table-border: 1px solid #000;
}
th, td {
  border-left: var(--table-border);
  border-top: var(--table-border);
  cursor: pointer;
}
:is(th, td):last-child {
  border-right: var(--table-border);
}
tr:last-child :is(th, td) {
  border-bottom: var(--table-border);
}

#tableContextMenu {
  width: 40px;
  height: 20px;
  font-size: 10px;
  color: #fff;
  background-color: #303133;
  border-radius: 2px;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  position: absolute;
  z-index: 999;
}